2001 Buick LeSabre Custom Intermittent P0405 Code

[Ruptoo]

For the past week or so my "Service Engine Soon" light has been going on and off. One day it'll be on, the next day off. Just scanned the code today and it came up as P0405. Went and looked at the EGR valve to make sure the connection wasn't loose and noticed that the top black plastic part where the cable connects to the EGR moves up and down if pressed on. Just wondering what next steps/thoughts might be.

 

[MelsRegal]

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Thread '2001 Buick LeSabre Intermittent P0405 Code'

Aug 1, 2025

Over the past week I've had my "Service Engine Soon" light come off and on. One day it'll be on while driving, the next it won't. Just got to scanning it today and it's showing a P0405 code. Went to check the EGR valve plug and wiring (those look fine) and noticed that the top black plastic part of the EGR valve moves up and down when pressed on. Has anyone experienced this or have any recommendations?

• Ruptoo
• Replies: 3
• Forum: Buick LeSabre Forum